Field of the Invention
The present invention relates to a fire extinguishing apparatus suitable for fire extinction for a fire extinguishing object such as a high-temperature operable battery.
Description of Related Art
A battery system using sodium-sulfur batteries is constituted by combination of multiple battery modules each housing hundreds of battery cells in a thermal insulating enclosure. In case of firing of such a battery module, hot molten material of sodium and sulfur blows out to a ceiling surface of the thermal insulating enclosure, and when the hot molten material contacts air, a severe oxidation reaction occurs, which may cause enlargement of the fire. Since fire extinction with water is impossible due to existence of sodium, fire extinction by suffocation, in which air is shut off with use of fire extinguishing sand, is required. This battery charge system using the sodium-sulfur batteries may be several meters in height in a case of adopting a structure in which a plurality of battery modules are piled. Accordingly, a fire extinguishing apparatus is required to have ability to raise the fire extinguishing sand as high as several meters and spray it.
Patent Document 1 filed by the present applicant describes a fire extinguishing apparatus adapted to spray ceramic particles to an object under fire extinction. This apparatus has a structure in which the ceramic particles are housed in a storage tank and are delivered from a bottom portion of the storage tank with use of gas pressure applied to the storage tank from a gas cylinder.
However, in this apparatus, the storage tank has to be a pressure container since the storage tank needs to be pressurized at high pressure, which causes a problem of an increase in manufacturing cost and non-easy handling. Also, since the storage tank cannot be refilled with fire extinguishing sand during a fire extinguishing work, the amount of the fire extinguishing sand may be insufficient depending on the fire scale.